Electric car conversion: Project ForkenSwift

[MetroMPG]

skewbe suggests:

Can you solder the heck out of the end of the cable then hammer it flat and drill it? (or pre-flatten then solder then flatten and drill?)

We have a winner! I suggested exactly that to Ivan this evening.

PS - Ivan wasn't too happy with my home-made lugs (I will post some pics). He rightly pointed out that while the mechanical connection may be good, the flattened end of the copper pipe was much thinner than the lugs we have. So it wouldn't have had the same current capacity. Whether it would actually have been a problem or not in our application is another question...

[MetroMPG]

DIY vs OEM...

[MetroMPG]

OK, so directly flattening / soldering / flattening the cable end itself is the ticket. Weekend project - I'll have the FS operational again shortly (pun not intended).

[MetroMPG]

BigMouse asks where we got the cables...

All the cables on the car now came from the forklift (which is why the battery interconnects in this picture are 6 feet long!). Most of it's 4/0, but there's the odd length of 2/0 in there too.




We had a roll of used welding cable donated to us, but I'm not sure what gauge it is. 2/0 I thought. Have to stop in at Ivan's tomorrow to see. It might be worth dropping by a welding shop to see if they have anything they're willing to part with.

Do you know offhand how people generally route cables from one end of the vehicle to the other? I'm assuming underneath the car, in the exhaust/transmission tunnel. I was thinking we could get some plastic conduit and run it inside that for protection from the elements.

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Good news on the cable flattening / soldering / flattening process! I made 3 short cables this evening and I'm confident it's a workable solution to not spending any money on lugs. The ends are solid & more than thick enough. The FS will roll again this weekend . Pics to come.

[MetroMPG]

Rear flattened/soldered/flattened batt interconnects turned out well and are installed. Picked up 2 lengths of plastic 1 inch ID conduit as well. Continuing to plug away this afternoon...

[MetroMPG]

Show 'n' tell time... clicky zoomy



This is the flattened/soldered/flattened cable end vs OEM.



Finished cable installed.




Before & after. I made up 5 cables (2 up front not shown) - 10 cable ends made. I got a decent process worked out toward the end. There are more to do.



20 feet of well used 2/0 fine strand copper welding cable. Unfortunately, to connect the rear rack to the front we probably need around 24 feet. Ah well, I see splicing in my future...



Why this was donated to us: insulation damage. The wire itself looks OK though.



This is where the cables are now. I was thinking of leaving it like this, but passengers keep complaining. "Is this safe," they ask? "As long as you don't lick anything," I reply.



Got much of the conduit installed today. This is looking rearward from the driver's side. This section of conduit is in the area where the gas tank used to be, and inserts into the forward area of the spare tire well.

[MetroMPG]

I kept firing up the torches at the back of the car this afternoon, and every time I did I thought, "wait! gasoline fumes!"

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I don't think the cables will melt. Unless I really misunderstand what's going on, the 4/0 is WAAY overkill. The internal wiring inside the motor itself is more like 2/0 size. That's what I'm more concerned about melting...

In further "misunderstanding what's going on" news, today was the first time since the start of the project I mistakenly shorted out pack voltage. Freshly charged, too. !!!ZORCH!!! I vapourized the end of a 2/0 lug. :O

[MetroMPG]

That soldered cable end that turns into a lug is fantastic! Really, really good. Could you post up a tutorial so we don't all have to go through the learning curve please?

BigMouse:

I second this request!

Will do. I'll take some pics of the process when I make another one, sometime this week.

DAX:

Looking good Darin - I'm really impressed with the way you made terminal lugs.

[MetroMPG]

Thanks DaX.

Field tested the new cables/lugs today. 8 km, not even warm to the touch. I don't think they'll be a problem.

Fourthbean: yes, some of the metal is missing now. It was just a glancing touch, fortunately.

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Met up with Ivan tonight to start planning where to mount stuff under the hood. That means soon the controller will no longer be ratchet-strapped on top of a hunk of styrofoam on top of the transaxle!

I'll start with the controller, which will be mounted separately behind the driver's side headlight area, then we'll have to come up with some kind of a platform for the contactors, fuses, shunt, etc. Probably mount them over the transaxle.

The mounting criteria are: 1) don't block access to the front 2 batts, for easy removal; 2) don't obstruct the view of the motor (for show 'n' tell purposes only).

Of course the place with the most amount of room to easily mount all this stuff would violate both criteria.

Once this stuff is mounted and the wiring/cabling tidied up, I'm taking the ForkenSwift to the mechanic so we can get it licenced.

[MetroMPG]

Ben: Should I ask for range/speed predictions?

We've already got a pretty good idea: around 20 km of around-town (side streets) driving; top speed is around 60 km/h with a lo-o-o-o-ong runway. This is on the Cursit controller. We can get faster if we get a better controller or install a bypass circuit for turbo boost.

The batteries are tired though. The voltage sags pretty low under even light-modest loads. I've read it's best to try to keep the batts above 5.75v (individually) under load, and definitely go no lower than 5.5v. I can't accelerate at "normal" traffic rates and keep the voltage above 5.75, even on a fresh charge.

Even on the new batteries you got from that pick up truck fella?

Ben: yup, that's on our "good" batteries. Keep in mind he had already used them daily for 2 [edit - actually 3] years, and was essentially ready to recycle them.